View Compilation Error

0_0_20899557_21829.cpp: In function 'int main()':
0_0_20899557_21829.cpp:29:15: error: 'i' was not declared in this scope
         repf (i, 0, len - 1){  
               ^
0_0_20899557_21829.cpp:29:28: error: 'repf' was not declared in this scope
         repf (i, 0, len - 1){  
                            ^